This invention relates generally to methods and systems for capturing biometric data, and more particularly, to methods and systems for capturing biometric data from biometric characteristics positioned freely in space.
Biometric data is generally captured under controlled conditions during enrollment in authentication systems and during authentication transactions. Such conditions generally include placing a biometric characteristic on a surface such as a platen in a known steady position, applying known illumination to the biometric characteristic, and locating a biometric capture device in a fixed position with respect to, and at a fixed distance from, the platen. Very high quality biometric data is typically captured from biometric characteristics subject to such controlled conditions. However, exercising control over such conditions is generally expensive and is inconvenient for users.
Known techniques for capturing biometric data from biometric characteristics positioned freely in space generally require at least some control over conditions during capture. For example, individuals may be instructed to align a biometric characteristic positioned freely in space with an outline on a surface such as a platen to capture biometric data in a predetermined alignment. However, when capturing biometric data from biometric characteristics positioned freely in space it is difficult to control conditions affecting the quality of biometric data that may be captured. For example, biometric characteristics positioned freely in space may not be placed in a known steady position with respect to a biometric data capture device during capture. Moreover, applying illumination to biometric characteristics positioned freely in space may cause some features of the biometric characteristic to be visible and others to be invisible. The inability to control conditions while capturing biometric data from biometric characteristics positioned freely in space has been known to negatively affect the quality of captured biometric data, and as a result has also been known to negatively affect the accuracy of biometric authentication transaction results.